1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Copyright (C) 2015 Free Electrons
  4 * Copyright (C) 2015 NextThing Co
  5 *
  6 * Maxime Ripard <maxime.ripard@free-electrons.com>
  7 */
  8
  9#include <linux/clk.h>
 10
 11#include <drm/drm_atomic_helper.h>
 12#include <drm/drm_bridge.h>
 13#include <drm/drm_of.h>
 14#include <drm/drm_panel.h>
 15#include <drm/drm_print.h>
 16#include <drm/drm_probe_helper.h>
 17#include <drm/drm_simple_kms_helper.h>
 18
 19#include "sun4i_crtc.h"
 20#include "sun4i_tcon.h"
 21#include "sun4i_rgb.h"
 22
 23struct sun4i_rgb {
 24	struct drm_connector	connector;
 25	struct drm_encoder	encoder;
 26
 27	struct sun4i_tcon	*tcon;
 28	struct drm_panel	*panel;
 29	struct drm_bridge	*bridge;
 30};
 31
 32static inline struct sun4i_rgb *
 33drm_connector_to_sun4i_rgb(struct drm_connector *connector)
 34{
 35	return container_of(connector, struct sun4i_rgb,
 36			    connector);
 37}
 38
 39static inline struct sun4i_rgb *
 40drm_encoder_to_sun4i_rgb(struct drm_encoder *encoder)
 41{
 42	return container_of(encoder, struct sun4i_rgb,
 43			    encoder);
 44}
 45
 46static int sun4i_rgb_get_modes(struct drm_connector *connector)
 47{
 48	struct sun4i_rgb *rgb =
 49		drm_connector_to_sun4i_rgb(connector);
 50
 51	return drm_panel_get_modes(rgb->panel, connector);
 52}
 53
 54/*
 55 * VESA DMT defines a tolerance of 0.5% on the pixel clock, while the
 56 * CVT spec reuses that tolerance in its examples, so it looks to be a
 57 * good default tolerance for the EDID-based modes. Define it to 5 per
 58 * mille to avoid floating point operations.
 59 */
 60#define SUN4I_RGB_DOTCLOCK_TOLERANCE_PER_MILLE	5
 61
 62static enum drm_mode_status sun4i_rgb_mode_valid(struct drm_encoder *crtc,
 63						 const struct drm_display_mode *mode)
 64{
 65	struct sun4i_rgb *rgb = drm_encoder_to_sun4i_rgb(crtc);
 66	struct sun4i_tcon *tcon = rgb->tcon;
 67	u32 hsync = mode->hsync_end - mode->hsync_start;
 68	u32 vsync = mode->vsync_end - mode->vsync_start;
 69	unsigned long long rate = mode->clock * 1000;
 70	unsigned long long lowest, highest;
 71	unsigned long long rounded_rate;
 72
 73	DRM_DEBUG_DRIVER("Validating modes...\n");
 74
 75	if (hsync < 1)
 76		return MODE_HSYNC_NARROW;
 77
 78	if (hsync > 0x3ff)
 79		return MODE_HSYNC_WIDE;
 80
 81	if ((mode->hdisplay < 1) || (mode->htotal < 1))
 82		return MODE_H_ILLEGAL;
 83
 84	if ((mode->hdisplay > 0x7ff) || (mode->htotal > 0xfff))
 85		return MODE_BAD_HVALUE;
 86
 87	DRM_DEBUG_DRIVER("Horizontal parameters OK\n");
 88
 89	if (vsync < 1)
 90		return MODE_VSYNC_NARROW;
 91
 92	if (vsync > 0x3ff)
 93		return MODE_VSYNC_WIDE;
 94
 95	if ((mode->vdisplay < 1) || (mode->vtotal < 1))
 96		return MODE_V_ILLEGAL;
 97
 98	if ((mode->vdisplay > 0x7ff) || (mode->vtotal > 0xfff))
 99		return MODE_BAD_VVALUE;
100
101	DRM_DEBUG_DRIVER("Vertical parameters OK\n");
102
103	/*
104	 * TODO: We should use the struct display_timing if available
105	 * and / or trying to stretch the timings within that
106	 * tolerancy to take care of panels that we wouldn't be able
107	 * to have a exact match for.
108	 */
109	if (rgb->panel) {
110		DRM_DEBUG_DRIVER("RGB panel used, skipping clock rate checks");
111		goto out;
112	}
113
114	/*
115	 * That shouldn't ever happen unless something is really wrong, but it
116	 * doesn't harm to check.
117	 */
118	if (!rgb->bridge)
119		goto out;
120
121	tcon->dclk_min_div = 6;
122	tcon->dclk_max_div = 127;
123	rounded_rate = clk_round_rate(tcon->dclk, rate);
124
125	lowest = rate * (1000 - SUN4I_RGB_DOTCLOCK_TOLERANCE_PER_MILLE);
126	do_div(lowest, 1000);
127	if (rounded_rate < lowest)
128		return MODE_CLOCK_LOW;
129
130	highest = rate * (1000 + SUN4I_RGB_DOTCLOCK_TOLERANCE_PER_MILLE);
131	do_div(highest, 1000);
132	if (rounded_rate > highest)
133		return MODE_CLOCK_HIGH;
134
135out:
136	DRM_DEBUG_DRIVER("Clock rate OK\n");
137
138	return MODE_OK;
139}
140
141static const struct drm_connector_helper_funcs sun4i_rgb_con_helper_funcs = {
142	.get_modes	= sun4i_rgb_get_modes,
143};
144
145static void
146sun4i_rgb_connector_destroy(struct drm_connector *connector)
147{
148	drm_connector_cleanup(connector);
149}
150
151static const struct drm_connector_funcs sun4i_rgb_con_funcs = {
152	.fill_modes		= drm_helper_probe_single_connector_modes,
153	.destroy		= sun4i_rgb_connector_destroy,
154	.reset			= drm_atomic_helper_connector_reset,
155	.atomic_duplicate_state	= drm_atomic_helper_connector_duplicate_state,
156	.atomic_destroy_state	= drm_atomic_helper_connector_destroy_state,
157};
158
159static void sun4i_rgb_encoder_enable(struct drm_encoder *encoder)
160{
161	struct sun4i_rgb *rgb = drm_encoder_to_sun4i_rgb(encoder);
162
163	DRM_DEBUG_DRIVER("Enabling RGB output\n");
164
165	if (rgb->panel) {
166		drm_panel_prepare(rgb->panel);
167		drm_panel_enable(rgb->panel);
168	}
169}
170
171static void sun4i_rgb_encoder_disable(struct drm_encoder *encoder)
172{
173	struct sun4i_rgb *rgb = drm_encoder_to_sun4i_rgb(encoder);
174
175	DRM_DEBUG_DRIVER("Disabling RGB output\n");
176
177	if (rgb->panel) {
178		drm_panel_disable(rgb->panel);
179		drm_panel_unprepare(rgb->panel);
180	}
181}
182
183static const struct drm_encoder_helper_funcs sun4i_rgb_enc_helper_funcs = {
184	.disable	= sun4i_rgb_encoder_disable,
185	.enable		= sun4i_rgb_encoder_enable,
186	.mode_valid	= sun4i_rgb_mode_valid,
187};
188
189int sun4i_rgb_init(struct drm_device *drm, struct sun4i_tcon *tcon)
190{
191	struct drm_encoder *encoder;
192	struct sun4i_rgb *rgb;
193	int ret;
194
195	rgb = devm_kzalloc(drm->dev, sizeof(*rgb), GFP_KERNEL);
196	if (!rgb)
197		return -ENOMEM;
198	rgb->tcon = tcon;
199	encoder = &rgb->encoder;
200
201	ret = drm_of_find_panel_or_bridge(tcon->dev->of_node, 1, 0,
202					  &rgb->panel, &rgb->bridge);
203	if (ret) {
204		dev_info(drm->dev, "No panel or bridge found... RGB output disabled\n");
205		return 0;
206	}
207
208	drm_encoder_helper_add(&rgb->encoder,
209			       &sun4i_rgb_enc_helper_funcs);
210	ret = drm_simple_encoder_init(drm, &rgb->encoder,
211				      DRM_MODE_ENCODER_NONE);
212	if (ret) {
213		dev_err(drm->dev, "Couldn't initialise the rgb encoder\n");
214		goto err_out;
215	}
216
217	/* The RGB encoder can only work with the TCON channel 0 */
218	rgb->encoder.possible_crtcs = drm_crtc_mask(&tcon->crtc->crtc);
219
220	if (rgb->panel) {
221		drm_connector_helper_add(&rgb->connector,
222					 &sun4i_rgb_con_helper_funcs);
223		ret = drm_connector_init(drm, &rgb->connector,
224					 &sun4i_rgb_con_funcs,
225					 DRM_MODE_CONNECTOR_Unknown);
226		if (ret) {
227			dev_err(drm->dev, "Couldn't initialise the rgb connector\n");
228			goto err_cleanup_connector;
229		}
230
231		drm_connector_attach_encoder(&rgb->connector,
232						  &rgb->encoder);
233	}
234
235	if (rgb->bridge) {
236		ret = drm_bridge_attach(encoder, rgb->bridge, NULL, 0);
237		if (ret)
238			goto err_cleanup_connector;
239	}
240
241	return 0;
242
243err_cleanup_connector:
244	drm_encoder_cleanup(&rgb->encoder);
245err_out:
246	return ret;
247}
248EXPORT_SYMBOL(sun4i_rgb_init);